{
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\begin{tabular}{l*{3}{cccc}}
\hline\hline
                    &\multicolumn{2}{c}{(1)}  &\multicolumn{2}{c}{(2)}  &\multicolumn{2}{c}{(3)}           \\
                    &\multicolumn{2}{c}{}     &\multicolumn{2}{c}{}     &\multicolumn{2}{c}{}              \\
                    &        mean&          sd&        mean&          sd&           b         &           p\\
\hline
Age                 &       19.09&        1.24&       19.00&        1.13&        0.10         &      (0.28)\\
Female              &        0.47&        0.50&        0.51&        0.50&       -0.03         &      (0.35)\\
STEM                &        0.33&        0.47&        0.30&        0.46&        0.02         &      (0.53)\\
Mock overall score  &       -0.03&        0.98&        0.02&        1.01&       -0.06         &      (0.45)\\
Mock principal score&       -0.02&        0.96&        0.02&        1.04&       -0.04         &      (0.72)\\
Mock subsidiary score&       -0.01&        1.05&        0.01&        0.96&       -0.03         &      (0.75)\\
\hline
Observations        &         340&            &         368&            &         708         &            \\
\hline\hline
\end{tabular}
}
